So called boat leveling devices of the trim tab type have been known for many years and various forms of them have been developed in an effort to maximize attitude control, stability of the marine craft and general hydrodynamic efficiency inclusive of decrease of flow velocity under the hull and fuel efficiency.
The prior art trim tabs are typically provided in pairs to enhance stability of the craft, which are attached directly to the transom of a watercraft and in which the attitude of the trim tab is controlled through a hydraulic piston assembly which controls relative angulation of the whole relative to level of the water.
In general trim tabs of the prior art, whether double or single acting, will operate upon the same principles and have a common objective, namely, that of contributing to the efficiency control of the boats attitude, stabilization and general hydrodynamics.
In recent years, most efforts of the prior art have been directed primary to improvement of the electronics in the development of algorithms to optimize trim tab control under various conditions of speed, shape of the boat's hull, having distribution in craft, and other hydrodynamic considerations. The prior art also has experimented with the efficiency of electric motor controls of the trim tab as opposed to that of the hydraulic systems.
The trim tabs of the prior art contain a trim tab secured to the hull or transom of a boat with a fixed hinge. When this hinge is fixed, it requires the actuator to be mounted on an angle other than 90 degrees. Placement difficulties arise when the trim tab is mounted under the hull, rather than to the transom of the boat. A need exists for a fluid hinge that allows an actuator to be secured to the transom of the boat, while offering a non-fixed connection of the front of the planar surface of the trim tab to the hull of the boat.